/***
 * ASM Guide
 * Copyright (c) 2007 Eric Bruneton, 2011 Google
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

package cn.zwy.day3;

import static org.objectweb.asm.Opcodes.ACC_PRIVATE;
import static org.objectweb.asm.Opcodes.ACC_PUBLIC;
import static org.objectweb.asm.Opcodes.ACC_SUPER;
import static org.objectweb.asm.Opcodes.V1_6;

import java.io.File;
import java.io.FileOutputStream;
import java.io.PrintWriter;

import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.FieldVisitor;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Type;
import org.objectweb.asm.commons.GeneratorAdapter;
import org.objectweb.asm.commons.Method;
import org.objectweb.asm.util.CheckClassAdapter;
import org.objectweb.asm.util.TraceClassVisitor;

/**
 * ASM Guide example class.
 * 
 * @author Eric Bruneton
 */
public class BeanGenerator2 {

    public static byte[] generate(PrintWriter printWriter) {
        ClassWriter cv = new ClassWriter(ClassWriter.COMPUTE_MAXS);
        cv.visit(52, ACC_PUBLIC + ACC_SUPER, "cn/zwy/day3/Bean", null, "java/lang/Object", null);
        cv.visitSource("Bean.java", null);
        FieldVisitor fv = cv.visitField(ACC_PRIVATE, "f", "I", null, null);
        if (fv != null) {
            fv.visitEnd();
        }
        MethodVisitor mv;
        mv = cv.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
        if (mv != null) {
            Method m = Method.getMethod("void <init>()");
            GeneratorAdapter ga = new GeneratorAdapter(ACC_PUBLIC, m, mv);
            ga.visitCode();
            ga.loadThis();
            ga.invokeConstructor(Type.getType("Ljava/lang/Object;"), m);
            ga.returnValue();
            ga.endMethod();
        }
        mv = cv.visitMethod(ACC_PUBLIC, "getF", "()I", null, null);
        if (mv != null) {
            Type bean = Type.getType("Lpkg/Bean;");
            Method m = Method.getMethod("int getF()");
            GeneratorAdapter ga = new GeneratorAdapter(ACC_PUBLIC, m, mv);
            ga.visitCode();
            ga.loadThis();
            ga.getField(bean, "f", Type.INT_TYPE);
            ga.returnValue();
            ga.endMethod();
        }
        mv = cv.visitMethod(ACC_PUBLIC, "setF", "(I)V", null, null);
        if (mv != null) {
            Type bean = Type.getType("Lpkg/Bean;");
            Method m = Method.getMethod("void setF(int)");
            GeneratorAdapter ga = new GeneratorAdapter(ACC_PUBLIC, m, mv);
            ga.visitCode();
            ga.loadThis();
            ga.loadArg(0);
            ga.putField(bean, "f", Type.INT_TYPE);
            ga.returnValue();
            ga.endMethod();
        }
        mv = cv.visitMethod(ACC_PUBLIC, "checkAndSetF", "(I)V", null, null);
        if (mv != null) {
            Type bean = Type.getType("Lpkg/Bean;");
            Method m = Method.getMethod("void checkAndSetF(int)");
            GeneratorAdapter ga = new GeneratorAdapter(ACC_PUBLIC, m, mv);
            ga.visitCode();
            ga.loadArg(0);
            Label label = new Label();
            ga.ifZCmp(GeneratorAdapter.LT, label);
            ga.loadThis();
            ga.loadArg(0);
            ga.putField(bean, "f", Type.INT_TYPE);
            Label end = new Label();
            ga.goTo(end);
            ga.mark(label);
            ga.throwException(Type.getType(IllegalArgumentException.class), "f");
            ga.mark(end);
            ga.returnValue();
            ga.endMethod();
        }
        cv.visitEnd();
        return cv.toByteArray();
    }

    public static void main(String[] args) throws Exception {
        byte[] b2 = generate(null);
        FileOutputStream fos = new FileOutputStream(new File("D:\\bytecode", "random.class"));
        fos.write(b2, 0, b2.length);
        fos.flush();
        fos.close();
    }
}
